McCarthy, 30, is 2-4 with a 5.00 ERA (37 ER in 66.2 IP) in 11 starts with the D-backs this season, including a 2-1 mark with a 2.36 ERA (7 ER in 26.2 IP) in his last 7 starts. He was placed on the 15-day disabled list on June 1 (retro to May 31) with right shoulder inflammation and made 2 rehab starts with Triple-A Reno.

McCarthy will start today's game at Boston, his first outing since May 30 at Texas.

Sipp, 30, was 3-1 with a 3.94 ERA (14 ER in 32.0 IP) in 47 games with Arizona in 2013. He was acquired as part of a 3-team trade with Cincinnati and Cleveland on Dec. 10, 2012.